YOKOGAWA PH202S - Page 126

IM 12B07D02-01E
12-14 Appendix
2/3
QIS 12B07D02-71E
Table 1
Reference Temperature
(°C)
Resistance Box Resistance
(:)
Data Display
(°C)
-20 921.6 -20.0 ±0.3
+25 1097.3 +25.0 ±0.3
+130 1498.3 +130.0 ±0.3
3.4 pH Indication Check
Set the instrument as follows.
Decade resistance box: 1000 
Change the simulation input value of the standard voltage generator as shown in Table 2. The
corresponding pH data must be within the range.
Table 2
Check Point (pH) Simulation Input (mV) Data Display (pH)
0 +414.1 0.00 ±0.01
7 0.0 7.00 ±0.01
14 -414.1 14.00 ±0.01
3.5 ORP Indication Check
Put the instrument in ORP mode by following the steps below.
a. Press the [] key. The message display will show “SERV.”
b. Press the [YES] key. The message display will show “CODE” and the data display will
show “00” with the first digit of 0 flashing.
c. Press the [>] key once. The second digit of 0 flashes.
d. Press the [
] key once. The data display will show “01” with 1 flashing.
e. Press the [ENT] key. The message display will show PH.ORP.”
f. Press the [
] key once. The data display will change from “0” to “1.”
g. Press the [ENT] key.
h. Turn on power again.
In this state, change the simulation input of the standard voltage generator as shown in Table 3.
The corresponding data must be within the range.
Table 3
Simulation Input (mV) Data Display (mV)
-1500 -1500 ±1
0 0 ±1
+1500 +1500 ±1
Return to PH mode by following the steps below and then the tests are completed.
a. Press the [] key. The message display will show “SERV.”
b. Press the [YES] key. The message display will show “CODE” and the data display will
show “00” with the first digit of 0 flashing.
c. Press the [>] key once. The second digit of 0 flashes.
d. Press the [
] key once. The data display will show “01” with 1 flashing.
e. Press the [ENT] key. The message display will show PH.ORP.”
f. Press the [
] key once. The data display will change from “1” to “0.”
g. Press the [ENT] key.